A dryshaver with a catch electrode for attracting beard stubble

ABSTRACT

In a dryshaver there is provided a catch electrode for attracting beard stubble and the like, having a carrier of electrically non-conductive material and provided on opposite sides with a grid-shaped electrically conductive first layer and an continuous electrically conductive second layer. A counterelectrode is juxtaposed with but spaced from the first layer, and the counter-electrode and the second layer are connected to respective poles of a source of electrical energy, whereas the first layer is connected to a second source of electrical energy whose potential is no greater than that of the first source.

United States Patent 1 [1 1 3,769,497 Kuhl et al. [451 Sept. 25, 1973 DRYSHAVER WITH A CATCH ELECTRODEFOR ATTRACTING BEARD STUBBLE Inventors: Adolf Kuhl, Hannover; Hans Dieter Huber, Niederhochstadt; l-lelmut Bollmann, Frankfurt, all of Germany Assignee: Braun Aktiengesellschait,

Frankfurt/Main, Germany Filed: June 23, 1972 'Appl. No.1 265,775

Foreign Application Priority Data References Cited UNITED STATES PATENTS Anna 30/4l.6 X

FOREIGN PATENTS OR APPLICATIONS 2,001,423 10/1970 Germany ..30/4l.6

Primary Examiner-Othell M. Simpson Assistant Examiner-Gary L. Smith Attorney-Michael S. Striker [57] ABSTRACT In a dryshaver there is provided a catch electrode for attracting beard stubble and the like, having a carrier of electrically non-conductive material and provided on opposite sides with a grid-shaped electrically conductive first layer and an continuous electrically conductive second layer. A counter-electrode is juxtaposed with but spaced from the first layer, and the counter-electrode and the second layer are connected to respective poles of a source of electrical energy, whereas the first layer is connected to a second source of electrical energy whose potential is no greater than that of the first source.

6 Claims, 3 Drawing Figures DRYSHAVER WITH A CATCH ELECTRODE FOR ATTRACTING BEARD STUBBLE BACKGROUND OF THE INVENTION The present invention relates generally to a shaver, and in particular to a dryshaver. Still more particularly the present inventionrelates, in a dryshaver, to an arrangement for attracting beard stubble with the aid of an electrical field established between electrodes.

The concept of attracting and retaining cut-off beard stubble to an electrode in an electrically operated dryshaver, isalready known per se. The, prior art proposes to utilize two electrodes between which an electrical field of high intensity is established. The beard stubble, that is the cut-off beard hair, becomes charged in the electrical field and is then attracted by one of the electrodes, the so-called catch electrode. The purpose of such arrangements is two-fold, namely on the one hand it is intended to suppress the distribution of the beard stubblethroughout the shear head of the dryshaver, and on the other hand it is intended to prevent the undesirable exiting of the beard stubble from the dryshaver during and after use of the same, for instance through the holes in the shear foil.

The difficulty with the prior-art proposals is that it is not readily possible to maintain the strength of the electric field at a sufficient level to assure proper charging and attraction and retention of the beard stubble at the catch electrode. On the other hand this must of course be accomplished with the minimum possible amount of technical expenditure for producing the electrical field, because the voltage required for establishing the field must be produced in the rather small dryshaver itself so that space availability is quite evidently limited for the accommodation of the various technical means required.

The obvious approach has been to arrange the catch electrode and the counter-electrode as close to one another as possible, in order to be able to produce a relatively strong electrical field between them with a small technical expenditure, and in particular with a small potential, not only to reduce the space requirements but also to reduce the insulating problems involved. It has been found, however, that the results obtained with this approach in the prior art are not entirely satisfactory.

Moreover, it has been found that structural limitations imposed by the construction of such dryshavers make it impossible to bring the catch electrodeand the counter-electrode as close together as would be desir able from a point of view of the above-mentioned considerations. Also, it has been proposed to provide on the catch electrode replaceable surface layers which are intended to retain the attracted beard stubble, but here again it has been found that this is not satisfactory and that such surface layers are incapable of sufficiently retaining the beard stubble.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to overcome the disadvantages of the prior art as outlined above.

More particularly it is an object of the present invention to provide an improveddryshaver construction in which these problems areovercome.

Still more particularly it is an object of the present invention to provide, in a dryshaver, an arrangement in LII which beard stubble can be attracted to and retained on the catch electrode substantially more efficaciously than heretofore the case.

Another object of the invention is to provide such an arrangement in which it is possible to assure that the beard stubble is retained at areas or positions which can be precisely predetermined, but without requiring excessive technical expenditures for obtaining the necessary potential required to establish the electrical field.

In pursuance of these objects, and of others which will become apparent hereafter, one feature of the invention resides in a dryshaver, and in particular in a combination in such a dryshaver, which comprises catch electrode means for attracting beard stubble and the like, such catch electrode means comprising a carrier member of electrically non-conductive material (having a dielectric constant greater than one) and which is provided with two opposite sides on one of which there is located a grid-shaped electrical conductive first layer and on the other of which there is cated a continuous electrically conductive second layer. The erm continuous is intended to designate a condition in which the interstices present in the gridshaped first layer are not present, so that the second layer is not interrupted. A counter electrode is juxtaposed with but spaced from the first layer, and a first source of electrical energy has one pole connected with the second layer and an outer pole connected with the counter-electrode. A second source of electrical. energy, having a potential at most equal to that of the first source, is connected with the first layer. With this construction it is possible to utilize relatively low potential but nevertheless to create an electrical field which is substantial enough to permit proper charging 'of the cut-off beard stubble, and to attract the charged beard stubble to the catch electrode means and to retain it thereon. This is true because at the transition between the insulating material of the carrier member and the conductive material of the grid-shaped first layer there occurs a field line concentration, that is a relatively strong non-homogeneous electrical field. It is here that the beard stubble is attracted. Moreover, by appropriately configurating the grid-shaped first layer it is possible to precisely determine the position and intensity of the electrical field created, and thereby to predetermine at will the locations at which the beard stubble will be retained on the catch electrode means. Dryshavers usually have a cutter member composed of a plurality of blade portions, with the cutter member being elongated and hollow, frequently having a semicylindrical cross-section. According to an advantageous concept of the invention the catch electrode means may extend longitudinally in and through the hollow cutter member, a construction in which a particularly small spacing can be obtained between the electrodes between which the electrical field is established, that is the catch electrode means and the counter-electrode. This is especially true if the counterelectrode is the shear foil, that is the thin metallic foil which is provided with apertures for passage of the beard stubble and which overlies the movable cutter member. Such a construction has the additional advantage of great simplicity because it eliminates the necessity for providing a separate counter-electrode, utilizing the already existing shear foil as the counterelectrode. In such a construction it is advantageous if the catch electrode is arcuately curved in conformance with any arcuate curvature of the cutter member itself, which is usually curved in direction transversely of its elongation.

It is also advantageous if the catch electrode is arcuately curved in conformance with the curvature if anyof the counter-electrode, especially if the counter-electrode is constituted by the shear foil which is in most instances arcuately curved over the cutter member. In such a construction the electrical field between the electrodes can be homogeneous.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof. will be best understood from the following description of spcific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a greatly simplified perspective view illustrating an embodiment of the present invention;

FIG. 2 is a sectional view, on an enlarged scale, taken on line IIII of FIG. 1; and

FIG. 3 is a simplified perspective view illustrating a dryshaver provided with another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly the embodiment illustrated in FIGS. 1 and 2 it will be seen that reference numeral 2 designates a counter electrode which is shown in broken lines and which shall here be assumed to be the shear foil ofa dryshaver. Such dryshavers have a housing and a shaving head, for instance as shown in FIG. 3, and are too well known to require a detailed discussion. It will be appreciated however, that the shaving head carries a thin flexible foil of metallic material provided with apertures through which the beard stubble extends into the interior of the head and into contact with the cutter element which cuts it off. The embodiment in FIGS. 1 and 2 assumes that the counter-electrode 2 is here constituted by this shear foil.

There is further provided a catch electrode juxtaposed with the counter-electrode 2 and between which an electrical field is established by connecting the two electrodes to a high-potential direct current source. The catch electrode is in form of a carrier member 1 of electrically non-conductive material, of which any non-conductive material is suitable which has a dielectric constant higher than 1. One of the sides of the essentially plate-shaped carrier member 1 carries a first layer 3 of electrically conductive material, the layer 3 being essentially grid-shaped, that is having interstices as shown. The opposite side of the member 1 carries a second layer 4 of electrically conductive material which, however, is continuous, i.e., it is not provided with the interstices of the grid-shaped layer 3.

A source of direct current is identified with reference numeral 6, having a pole 9 which is connected with the layer 4 and another pole 10 which is connected with the counter-electrode 2, that is here with the shear foil. An additional source of electrical current is identified with reference numeral 7 and has a potential which is no higher than that of the first source 6; the source 7 is connected with the layer 3, as shown in FIG. 1.

The manner in which the electrical potential of the sources 6 and 7 is produced in the dryshaver, requires no detailed discussion, being known per se to those skilled in the art. The layers 3 and 4 may be provided in various ways, for instance they may be vapordeposited metallic material, they may be electrically conductive paint or lacquer or the like.

FIG. 2 shows that when the sources 6 and 7 are connected as shown in FIG. 1, a field line distribution as illustrated will occur. The field lines 8 are shown in broken lines in FIG. 2 and it will be seen that at 8a, that is at the transition between the material of the member 1 and the material of the layer 3 there will occur a field line concentration, to which the cut-off beard stubble is attracted and where it will be retained. In other words, the location to which the beard stubble will be attracted and at which it will be retained, can be precisely predetermined by configurating the interstices of the grid-shaped first layer 3 as desired and appropriate.

Coming to the embodiment in FIG. 3 it will be seen that here there is shown a portion of the housing of a dryshaver, carrying the shaving head which has at its opposite ends the side walls 12 as shown. The reference numeral 5 in FIG. 3 designates the cutter member which is known from the art and which in known manner is of substantially semi-cylindrical hollow configuration as shown.

According to the invention the catch electrode 11 here extends in and through the hollow of the cutter element 5, longitudinally of the latter. Reference numeral 13 designates the motion transmitting component which is driven in suitable manner by the nonillustrated drive in the housing, and which transmits motion to the cutter member 5 in a sense reciprocating the same in the direction of the double-headed arrow.

The catch electrode 11, and also (as shown in FIG. 2) the catch electrode 1, 3, 4 will advantageously be arcuately curved in conformance with the similar curvature of the counter-electrode 2 and/or the cutter element 5. In the embodiment of FIG. 3 the electrodes 11 and 2 (the latter not shown in FIG. 3) are very close together, in that the shear foil constituting the electrode 2 closely overlies in arcuate curvature the upper or outer surface of the element 5. In such a construction it is advantageous to accommodate the curvature of electrode 11, electrode 2 and element 5 as closely as possible to one another, in order to obtain optimum results both in terms of space-reduction requirements and efficiency of operation.

It will be appreciated that the arrangement according to the present invention, and in particular the catch electrode means thereof, can be mounted in the dryshaver in known manner, for instance being connected with the shear head frame or being fixedly mounted in the side wall portions 12 of the shear head. It can also be made removable in a manner known per se, for facilitating cleaning and/or repairs.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a dryshaver, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to-be protected by Letters Patent is set forth in the appended claims:

1. In a dryshaver, a combination comprising catch electrode means for attracting beard stubble and the like, said catch electrode means comprising a carrier member of electrically non-conductive material and having two opposite sides, a grid-shaped electrically conductive first layer on one of said sides and a continuous electrically conductive second layer on the other of said sides; counter-electrode means juxtaposed with but spaced from said first layer; a first source of electrical engergy having one pole connected with said second layer and an other pole connected with said counter-electrode means; and a second source of electrical energy having a potential at most equal to that of said first source and being connected with said first layer.

2. A combination as defined in claim 1, wherein said material of said carrier member has a dielectric constant greater than 1.

3. A combination as defined in claim 1, wherein said second electrode means is a shear foil of said dryshaver.

4. A combination as defined in claim 1, said dryshaver further comprising a hollow elongated cutter element; and wherein said carrier member and layers extend within the hollow of said cutter element and longitudinally of the same.

5. A combination as defined in claim 4, said cutter element being arcuately curved transversely of its elongation; and wherein said carrier member is curved in at least substantial conformance with the curvature of said cutter element.

6. A combination as defined in claim 1, wherein said counter-electrode means is elongated and curved in direction transversely to its elongation; and wherein said carrier member is curved in at least substantial conformance with the curvature of said counter-electrode means. 

1. In a dryshaver, a combination comprising catch electrode means for attracting beard stubble and the like, said catch electrode means comprising a carrier member of electrically nonconductive material and having two opposite sides, a grid-shaped electrically conductive first layer on one of said sides and a continuous electrically conductive second layer on the other of said sides; counter-electrode means juxtaposed with but spaced from said first layer; a first source of electrical engergy having one pole connected witH said second layer and an other pole connected with said counter-electrode means; and a second source of electrical energy having a potential at most equal to that of said first source and being connected with said first layer.
 2. A combination as defined in claim 1, wherein said material of said carrier member has a dielectric constant greater than
 1. 3. A combination as defined in claim 1, wherein said second electrode means is a shear foil of said dryshaver.
 4. A combination as defined in claim 1, said dryshaver further comprising a hollow elongated cutter element; and wherein said carrier member and layers extend within the hollow of said cutter element and longitudinally of the same.
 5. A combination as defined in claim 4, said cutter element being arcuately curved transversely of its elongation; and wherein said carrier member is curved in at least substantial conformance with the curvature of said cutter element.
 6. A combination as defined in claim 1, wherein said counter-electrode means is elongated and curved in direction transversely to its elongation; and wherein said carrier member is curved in at least substantial conformance with the curvature of said counter-electrode means. 